Performance between PCIe 3.0 and 4.0:  Measured RX 6400 up to 35%

Performance between PCIe 3.0 and 4.0:  Measured RX 6400 up to 35%

Performance between PCIe 3.0 and 4.0:  Measured RX 6400 up to 35%.

AMD recently released the entry-level graphics card RX 6400.

Like the previous RX 6500 XT, it only supports PCIe 4.0 x4 system interface, with a one-way bandwidth of 8GB/s, equivalent to PCIe 3.0 x8.

TechPowerUp did an interesting test, examining the performance of 25 games and 3 resolutions of the RX 6400 in PCIe 4.0 x4 and PCIe 3.0 x4 modes to see how much difference it can make.

Looking directly at the results summary: In PCIe 3.0 mode, the RX 6400 lost 14% in 1080p/2K resolution performance, and plummeted by 23% in 4K resolution.

Of course, 2K/4K resolution doesn’t make much sense for a card of this caliber, but it does illustrate a trend.

The performance of different games is also very different. The PCIe 3.0 mode in “Assassin’s Creed: Valhalla” and “God of War” all lost up to 35% of the performance, while “The Witcher 3” is almost unchanged, the latter is mainly some old games.

In addition, for games that require large-capacity video memory, the RX 6400 4GB is easily insufficient.

At this time, it is necessary to borrow PCIe channels and system memory transmission resources, and PCIe 3.0 will become a bottleneck.

TPU recommendation, if you are still using PCIe 3.0 system, such as Intel 10th generation Core or earlier, AMD first generation Ryzen, don’t consider RX 6400, it is not as good as the previous RX 570 4GB, which is not expensive and supports full PCIe 3.0 x16, the game performance can be better, sometimes up to 17% higher than the RX 6400.

In addition, the RX 570 and even the RX 400 series still support FSR, which can further improve performance and image quality.